1. Field
Aspects of the present invention generally relate to an image forming apparatus, a method for controlling the image forming apparatus, and a storage medium.
2. Description of the Related Art
In recent years, with an increase in environmental consciousness, an image forming apparatus such as a copying machine has performed a function of shifting to a sleep mode to save power if the apparatus has not been used for a predetermined time or if a user has issued an instruction for shifting to a low power consumption state (sleep mode). For example, in the sleep mode, power supply to a printer unit or a scanner unit is stopped in order to achieve power saving while maintaining the convenience of the user as much as possible.
Further, there is an image forming apparatus which includes, in addition to a main central processing unit (CPU) for controlling each unit of the apparatus, a sub CPU having lower performance than that of the main CPU. When an error has occurred in the apparatus, power supply to the main CPU is stopped and only the sub CPU is caused to operate, so that the apparatus shifts to the sleep mode and power consumption is reduced (refer to Japanese Patent Application Laid-Open No. 2008-122917).
Furthermore, there is a technique in which, when an image forming apparatus wakes up from the sleep mode, only a part of the apparatus is initialized according to the content of an operation request serving as a wake-up trigger (refer to Japanese Patent Application Laid-Open No. 2003-241582). For example, if a print request is received in the sleep mode, the printer unit is initialized and the scanner unit is not initialized. In other words, if a print request is received, power is supplied to the printer unit and not to the scanner unit. Thus, in the technique discussed in Japanese Patent Application Laid-Open No. 2003-241582, when a request is received in the sleep mode, power is supplied only to a minimum portion necessary for responding to the request. As a result, power saving, prevention of noise, and an increase in the longevity of the apparatus are realized.
However, according to the above-described conventional techniques, if the apparatus shifts to the sleep mode while in a state where an error such as a paper jam has occurred and then receives a wake-up request which does not require the activation of the portion in which the paper jam has occurred, that portion is not initialized. Thus, there is a problem that power is not supplied to the portion in which the paper jam has occurred and the apparatus is unable to notify an operator of the paper jam error immediately after the apparatus wakes up from the sleep mode.
Further, in recent years, there has been an image forming apparatus including a human body detection sensor which allows the apparatus to wake up from the sleep mode more easily. With only an operator coming near the apparatus, the apparatus can wake up from the sleep mode. When such an apparatus wakes up from the sleep mode according to the human body detection serving as a trigger, the apparatus often does not supply power to the printer unit or the scanner unit so as to reduce power consumption as much as possible, similarly to the above-described apparatus. As a result, only waking up from the sleep mode does not allow the operator to notice that the paper jam has occurred. The operator notices that such an error has occurred, only after executing a job such as a copy function which uses the portion in which the error has occurred, so that the above-described problem is more apparent.